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Near-maxima of the two-dimensional Discrete Gaussian Free Field

Probability 2024-06-27 v3 Mathematical Physics math.MP

Abstract

We consider the Discrete Gaussian Free Field (DGFF) in domains DNZ2D_N\subseteq\mathbb Z^2 arising, via scaling by NN, from nice domains DR2D\subseteq\mathbb R^2. We study the statistics of the values order logN\sqrt{\log N} below the absolute maximum. Encoded as a point process on D×RD\times\mathbb R, the scaled spatial distribution of these near-extremal level sets in DND_N and the field values (in units of logN\sqrt{\log N} below the absolute maximum) tends, as NN\to\infty, in law to the product of the critical Liouville Quantum Gravity (cLQG) ZDZ^D and the Rayleigh law. The convergence holds jointly with the extremal process, for which ZDZ^D enters as the intensity measure of the limiting Poisson point process, and that of the DGFF itself; the cLQG defined by the limit field then coincides with ZDZ^D. While the limit near-extremal process is measurable with respect to the limit continuum GFF, the limit extremal process is not. Our results explain why the various ways to "norm" the lattice cLQG measure lead to the same limit object, modulo overall normalization.

Keywords

Cite

@article{arxiv.2010.13939,
  title  = {Near-maxima of the two-dimensional Discrete Gaussian Free Field},
  author = {Marek Biskup and Stephan Gufler and Oren Louidor},
  journal= {arXiv preprint arXiv:2010.13939},
  year   = {2024}
}

Comments

30 pages, AIHP format